Synthesis of new deuterium-labelled lignanolactones

Deuteration of several lignanolactones, using (H3PO4)-H-2 center dot BF3/(H2O)-H-2 as the deuteration reagent, is described, affording new stable isotopically pure polydeuterated lignans. All aromatic hydrogens are exchanged, including the less active ones. The order of H-1/H-2 exchange is studied by comparing calculated electrostatic potential values and experimental observations. Labile deuteriums are exchanged back to hydrogens with methanolic HCl to achieve stable isotopically pure compounds.